ganDL¶
In this project, we'll use generative adversarial networks to generate new images of faces from celebrities!
Get the Data¶
We'll be using two datasets in this project:
- MNIST
- CelebA
Since the celeb dataset is complex and you're doing GANs in a project for the first time, we want you to test your neural network on MNIST before CelebA. Running the GANs on MNIST will allow you to see how well your model trains sooner.
data_dir = './data'
"""
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"""
import helper
helper.download_extract('mnist', data_dir)
helper.download_extract('celeba', data_dir)
show_n_images = 25
"""
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"""
%matplotlib inline
import os
from glob import glob
from matplotlib import pyplot
mnist_images = helper.get_batch(glob(os.path.join(data_dir, 'mnist/*.jpg'))[:show_n_images], 28, 28, 'L')
pyplot.imshow(helper.images_square_grid(mnist_images, 'L'), cmap='gray')
CelebA¶
The CelebFaces Attributes Dataset (CelebA) dataset contains over 200,000 celebrity images with annotations. Since you're going to be generating faces, you won't need the annotations. You can view the first number of examples by changing show_n_images.
show_n_images = 25
"""
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"""
mnist_images = helper.get_batch(glob(os.path.join(data_dir, 'img_align_celeba/*.jpg'))[:show_n_images], 28, 28, 'RGB')
pyplot.imshow(helper.images_square_grid(mnist_images, 'RGB'))
Preprocess the Data¶
Since the project's main focus is on building the GANs, we have to preprocess the data. The CelebA images will be cropped to remove parts of the image that don't include a face, then resized down to 28x8. The values of the MNIST and CelebA dataset will be in the range of -0.5 to 0.5 of 28x28 dimensional images.
The MNIST images are black and white images with a single color channel while the CelebA images have 3 color channels (RGB color channel).
Build the Neural Network¶
We'll build the components necessary to build a GANs by implementing the following functions below:
model_inputsdiscriminatorgeneratormodel_lossmodel_opttrain
Check the Version of TensorFlow and Access to GPU¶
This will check to make sure you have the correct version of TensorFlow and access to a GPU
"""
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"""
from distutils.version import LooseVersion
import warnings
import tensorflow as tf
# Check TensorFlow Version
assert LooseVersion(tf.__version__) >= LooseVersion('1.0'), 'Please use TensorFlow version 1.0 or newer. You are using {}'.format(tf.__version__)
print('TensorFlow Version: {}'.format(tf.__version__))
# Check for a GPU
if not tf.test.gpu_device_name():
warnings.warn('No GPU found. Please use a GPU to train your neural network.')
else:
print('Default GPU Device: {}'.format(tf.test.gpu_device_name()))
Input¶
Implement the model_inputs function to create TF Placeholders for the Neural Network. It should create the following placeholders:
- Real input images placeholder tensor of rank 4 using
image_width,image_height, andimage_channels. - Z input placeholder with rank 2 using
z_dim. - Learning rate placeholder with rank 0.
Return the placeholders in the following the tuple (tensor of real input images, tensor of z data)
import problem_unittests as tests
def model_inputs(image_width, image_height, image_channels, z_dim):
"""
Create the model inputs
:param image_width: The input image width
:param image_height: The input image height
:param image_channels: The number of image channels
:param z_dim: The dimension of Z
:return: Tuple of (tensor of real input images, tensor of z data, learning rate)
"""
# Image Placeholder
real_inputs = tf.placeholder(tf.float32, (None, image_width, image_height,
image_channels), 'real_inputs')
# Z (?) Placeholder
z_inputs = tf.placeholder(tf.float32, (None, z_dim), 'z_inputs')
# Learning Rate
learning_rate = tf.placeholder(tf.float32, name='learning_rate')
return real_inputs, z_inputs, learning_rate
"""
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"""
tests.test_model_inputs(model_inputs)
Discriminator¶
Implement discriminator to create a discriminator neural network that discriminates on images.
This function should be able to reuse the variables in the neural network. We use tf.variable_scope with a scope name of "discriminator" to allow the variables to be reused.
The function should return a tuple: (tensor output of the discriminator, tensor logits of the discriminator).
def discriminator(images, reuse=False):
"""
Create the discriminator network
:param images: Tensor of input image(s)
:param reuse: Boolean if the weights should be reused
:return: Tuple of (tensor output of the discriminator, tensor logits of the discriminator)
"""
with tf.variable_scope('discriminator', reuse=reuse):
alpha = 0.1 # Alpa measure?
# 28 x 28 x out_channel_dim
x1 = tf.layers.conv2d(images, 64, 5, strides=2, padding='same')
relu1 = tf.maximum(alpha * x1, x1)
# 14 x 14 x 64
x2 = tf.layers.conv2d(relu1, 128, 5, strides=2, padding='same')
bn2 = tf.layers.batch_normalization(x2, training=True)
relu2 = tf.maximum(alpha * bn2, bn2)
# 7 x 7 x 128
x3 = tf.layers.conv2d(relu2, 256, 5, strides=2, padding='same')
bn3 = tf.layers.batch_normalization(x3, training=True)
relu3 = tf.maximum(alpha * bn3, bn3)
# 4 x 4 x 256
flat = tf.reshape(relu3, (-1, 4 * 4 * 256)) # Flatten
logits = tf.layers.dense(flat, 1) # Dense
out = tf.sigmoid(logits) # Activstion
return out, logits
"""
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"""
tests.test_discriminator(discriminator, tf)
Generator¶
We implement generator to generate an image using z!
This function should be able to reuse the variables in the neural network. Use tf.variable_scope with a scope name of "generator" to allow the variables to be reused. The function should return the generated 28 x 28 x out_channel_dim images.
def generator(z, out_channel_dim, is_train=True):
"""
Create the generator network
:param z: Input z
:param out_channel_dim: The number of channels in the output image
:param is_train: Boolean if generator is being used for training
:return: The tensor output of the generator
"""
with tf.variable_scope('generator', reuse=not is_train):
alpha = 0.1
x1 = tf.layers.dense(z, 7 * 7 * 512)
x1 = tf.reshape(x1, (-1, 7, 7, 512))
bn1 = tf.layers.batch_normalization(x1, training=is_train)
relu1 = tf.maximum(alpha * bn1, bn1)
# 7 x 7 x 512
conv2 = tf.layers.conv2d_transpose(relu1, 256, 5, strides=1, padding='same')
bn2 = tf.layers.batch_normalization(conv2, training=is_train)
relu2 = tf.maximum(alpha * bn2, bn2)
# 14 x 14 x 256
conv3 = tf.layers.conv2d_transpose(relu2, 128, 5, strides=2, padding='same')
bn3 = tf.layers.batch_normalization(conv3, training=is_train)
relu3 = tf.maximum(alpha * bn3, bn3)
# 28 x 28 x 128
logits = tf.layers.conv2d_transpose(relu3, out_channel_dim, 5, strides=2, padding='same')
# 28 x 28 x out_channel_dim
output = tf.tanh(logits)
return output
"""
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"""
tests.test_generator(generator, tf)
Loss¶
Here, we implement model_loss to build the GANs for training and calculate the loss. The function should return a tuple of (discriminator loss, generator loss). Use the following functions you implemented:
discriminator(images, reuse=False)generator(z, out_channel_dim, is_train=True)
def model_loss(input_real, input_z, out_channel_dim):
"""
Get the loss for the discriminator and generator
:param input_real: Images from the real dataset
:param input_z: Z input
:param out_channel_dim: The number of channels in the output image
:return: A tuple of (discriminator loss, generator loss)
"""
g_model = generator(input_z, out_channel_dim, True)
d_model_real, d_logits_real = discriminator(input_real, False)
d_model_fake, d_logits_fake = discriminator(g_model, True)
d_loss_real = tf.reduce_mean(
tf.nn.sigmoid_cross_entropy_with_logits(
logits=d_logits_real, labels=tf.ones_like(d_logits_real)))
d_loss_fake = tf.reduce_mean(
tf.nn.sigmoid_cross_entropy_with_logits(
logits=d_logits_fake, labels=tf.zeros_like(d_logits_fake)))
d_loss = d_loss_real + d_loss_fake
g_loss = tf.reduce_mean(
tf.nn.sigmoid_cross_entropy_with_logits(
logits=d_logits_fake, labels=tf.ones_like(d_logits_fake)))
return d_loss, g_loss
return None, None
"""
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"""
tests.test_model_loss(model_loss)
Optimization¶
Implement model_opt to create the optimization operations for the GANs. Use tf.trainable_variables to get all the trainable variables. Filter the variables with names that are in the discriminator and generator scope names. The function should return a tuple of (discriminator training operation, generator training operation).
def model_opt(d_loss, g_loss, learning_rate, beta1):
"""
Get optimization operations
:param d_loss: Discriminator loss Tensor
:param g_loss: Generator loss Tensor
:param learning_rate: Learning Rate Placeholder
:param beta1: The exponential decay rate for the 1st moment in the optimizer
:return: A tuple of (discriminator training operation, generator training operation)
"""
t_vars = tf.trainable_variables()
d_vars = [var for var in t_vars if var.name.startswith('discriminator')]
g_vars = [var for var in t_vars if var.name.startswith('generator')]
with tf.control_dependencies(tf.get_collection(tf.GraphKeys.UPDATE_OPS)):
d_train_opt = tf.train.AdamOptimizer(
learning_rate=learning_rate, beta1=beta1).minimize(
d_loss, var_list=d_vars)
g_train_opt = tf.train.AdamOptimizer(
learning_rate=learning_rate, beta1=beta1).minimize(
g_loss, var_list=g_vars)
return d_train_opt, g_train_opt
"""
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"""
tests.test_model_opt(model_opt, tf)
"""
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"""
import numpy as np
def show_generator_output(sess, n_images, input_z, out_channel_dim, image_mode):
"""
Show example output for the generator
:param sess: TensorFlow session
:param n_images: Number of Images to display
:param input_z: Input Z Tensor
:param out_channel_dim: The number of channels in the output image
:param image_mode: The mode to use for images ("RGB" or "L")
"""
cmap = None if image_mode == 'RGB' else 'gray'
z_dim = input_z.get_shape().as_list()[-1]
example_z = np.random.uniform(-1, 1, size=[n_images, z_dim])
samples = sess.run(
generator(input_z, out_channel_dim, False),
feed_dict={input_z: example_z})
images_grid = helper.images_square_grid(samples, image_mode)
pyplot.imshow(images_grid, cmap=cmap)
pyplot.show()
Train¶
Implement train to build and train the GANs. Use the following functions you implemented:
model_inputs(image_width, image_height, image_channels, z_dim)model_loss(input_real, input_z, out_channel_dim)model_opt(d_loss, g_loss, learning_rate, beta1)
Use the show_generator_output to show generator output while you train. Running show_generator_output for every batch will drastically increase training time and increase the size of the notebook. It's recommended to print the generator output every 100 batches.
def train(epoch_count, batch_size, z_dim, learning_rate, beta1, get_batches,
data_shape, data_image_mode):
"""
Train the GAN
:param epoch_count: Number of epochs
:param batch_size: Batch Size
:param z_dim: Z dimension
:param learning_rate: Learning Rate
:param beta1: The exponential decay rate for the 1st moment in the optimizer
:param get_batches: Function to get batches
:param data_shape: Shape of the data
:param data_image_mode: The image mode to use for images ("RGB" or "L")
"""
## Setup
n_samples, image_width, image_height, image_channels = data_shape # Input Shape
input_real, input_z, learn_rate = model_inputs(image_width, image_height,
image_channels, z_dim) # Input Real & Input Z
d_loss, g_loss = model_loss(input_real, input_z, image_channels) # Discriminator and Generator Loss Functions
d_opt, g_opt = model_opt(d_loss, g_loss, learning_rate, beta1) # Model Options (Loss, Hyperparameters)
iterations = int(n_samples / batch_size)
show_every = 100 # Logging
print_every = 10 # Stuff
n_images = 16 # Pretty
## Session
with tf.Session() as sess:
sess.run(tf.global_variables_initializer()) # run Session
for epoch_i in range(epoch_count):
# From step 0 in epoch_i
step = 0
# For image batch
for batch_images in get_batches(batch_size):
# Make two batchs
batch_images *= 2
# Increment Step
step += 1
# Sample random noise for G
batch_z = np.random.uniform(-1, 1, size=(batch_size, z_dim))
# Run Optimizers
# Discriminator
_ = sess.run(
d_opt,
feed_dict={
input_real: batch_images,
input_z: batch_z,
learn_rate: learning_rate
})
# Generator
_ = sess.run(
g_opt,
feed_dict={
input_z: batch_z,
input_real: batch_images,
learn_rate: learning_rate
})
# Print Loss
if step % print_every == 0:
train_loss_d = d_loss.eval({
input_real: batch_images,
input_z: batch_z
}) # Discriminator looks at loss between input_real:training and input_Z:generated results
train_loss_g = g_loss.eval({input_z: batch_z}) # Generator looks at input_z and batch_z only
print("Epoch {}/{}...".format(epoch_i + 1, epoch_count),
"Iter {}/{}...".format(step, iterations),
"Discriminator Loss: {:.4f}...".format(train_loss_d),
"Generator Loss: {:.4f}...".format(train_loss_g))
if step % show_every == 0:
# And Generated images!
show_generator_output(sess, n_images, input_z,
image_channels, data_image_mode)
print('finished.')
MNIST¶
Test your GANs architecture on MNIST. After 2 epochs, the GANs should be able to generate images that look like handwritten digits. Make sure the loss of the generator is lower than the loss of the discriminator or close to 0.
batch_size = 32
z_dim = 100
learning_rate = 0.001
beta1 = 0.5
"""
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"""
epochs = 2
mnist_dataset = helper.Dataset('mnist', glob(os.path.join(data_dir, 'mnist/*.jpg')))
with tf.Graph().as_default():
train(epochs, batch_size, z_dim, learning_rate, beta1, mnist_dataset.get_batches,
mnist_dataset.shape, mnist_dataset.image_mode)
CelebA¶
Run your GANs on CelebA. It will take around 20 minutes on the average GPU to run one epoch. You can run the whole epoch or stop when it starts to generate realistic faces.
batch_size = 32
z_dim = 100
learning_rate = 0.001
beta1 = 0.5
"""
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"""
epochs = 1
celeba_dataset = helper.Dataset('celeba', glob(os.path.join(data_dir, 'img_align_celeba/*.jpg')))
with tf.Graph().as_default():
train(epochs, batch_size, z_dim, learning_rate, beta1, celeba_dataset.get_batches,
celeba_dataset.shape, celeba_dataset.image_mode)
